Members of a survey team are sent from Earth in 2053 to Adrasteia, 75 light years away. The survey team are of two kinds: 'engrams', copies of earth-bound people, and artificial humans. Then, an alien race they call 'spinners' suddenly arrive and take up orbit around Adrasteia. Peter Alander, a flawed engram, is chosen to approach the aliens. What he finds is a wealth of knowledge, Artificial Intelligences, and a faster-than-light vessel — Arachne. Peter is nominated to return to Earth in this vessel, but an alien race is following in the footsteps of the Spinners, destroying everything. Who are they? Can humanity survive?